Here's my thread on NASIOC
Transmission crossmember front bolts torque - Subaru manual wrong? - NASIOC
The 2 17mm M12x1.25 bolts at the front of the transmission crossmember support calls for 103ft-lbs. Last time I took this part off, I did torque nearly to 97-100 ft-lbs, it didn't feel right at all.
Few days ago I removed it to install more bushings for the shifter and found 1 bolt had stretched threads and the hole of one of them had 1 thread that got stripped. My torque wrench is accurate and is calibrated so it's not about the tool issue.
I then checked around and found there are nominal values for fasteners like torque specs and loads.
http://www.imperialinc.com/pdf/A_FastenerTorqueCharts.pdf
Of course these aren't Subaru's materials but they represent somewhat average torque a certain bolt can take before it gets pulled beyond the limit.
If you check that link, a M12x1.25 grade 8.8 should be around 72 ft-lbs. Lets say there's 10% deviation, so put it at 80ft-lbs. 103ft-lbs is going way over and explains why my bolt was messed up. Now convert 103 N-m to ft-lbs and you'll get 75 ft-lbs. The near nominal value of a M12x1.25 bolt. Surprise surpise.
This seems like the same issue with the front caliper bolts. I think whoever wrote this tech document, didn't pass to QA at all, or if they did, QA sucks because as a QA engineer, I would never let things like mixed up torque values due to conversion go to production.
Either way, I don't think SOC/SOA/FHI would care that much about fixing this, but KNOWING about a rough guide to how fasteners have a nominal torque value can save you hassle and breaking stuff.
Transmission crossmember front bolts torque - Subaru manual wrong? - NASIOC
The 2 17mm M12x1.25 bolts at the front of the transmission crossmember support calls for 103ft-lbs. Last time I took this part off, I did torque nearly to 97-100 ft-lbs, it didn't feel right at all.
Few days ago I removed it to install more bushings for the shifter and found 1 bolt had stretched threads and the hole of one of them had 1 thread that got stripped. My torque wrench is accurate and is calibrated so it's not about the tool issue.
I then checked around and found there are nominal values for fasteners like torque specs and loads.
http://www.imperialinc.com/pdf/A_FastenerTorqueCharts.pdf
Of course these aren't Subaru's materials but they represent somewhat average torque a certain bolt can take before it gets pulled beyond the limit.
If you check that link, a M12x1.25 grade 8.8 should be around 72 ft-lbs. Lets say there's 10% deviation, so put it at 80ft-lbs. 103ft-lbs is going way over and explains why my bolt was messed up. Now convert 103 N-m to ft-lbs and you'll get 75 ft-lbs. The near nominal value of a M12x1.25 bolt. Surprise surpise.
This seems like the same issue with the front caliper bolts. I think whoever wrote this tech document, didn't pass to QA at all, or if they did, QA sucks because as a QA engineer, I would never let things like mixed up torque values due to conversion go to production.
Either way, I don't think SOC/SOA/FHI would care that much about fixing this, but KNOWING about a rough guide to how fasteners have a nominal torque value can save you hassle and breaking stuff.
